Secret levels are hidden areas in video games that players can discover, often containing unique challenges, rewards, or Easter eggs. These levels are not part of the main storyline and require players to complete specific tasks or find hidden items to access them. Players often enjoy secret levels because they add an element of surprise and exploration to the gaming experience. Popular games like Super Mario and The Legend of Zelda are known for their secret levels, which encourage players to think creatively and explore every corner of the game world.